One problem when sewing the stitches that surround a buttonhole on garments and the like on a buttonhole sewing machine is that oftentimes, the needle will be deflected as a result of the thickness of the fabric or the feeding of the fabric on the machine. This causes loopers associated with the buttonhole sewing machine mechanism to miss the thread extending through the eye of the needle, and as a result miss a stitch. This, in turn, causes flaws in the buttonholes.
Needle guides for sewing machines equipped with loopers have been proposed in the past, and one example of such a needle guide is disclosed in U.S. Pat. No. 1,276,393. In that particular device, there is a plurality of needles and a plurality of loopers for engaging the thread extending through the respective needles. Guides are positioned relative to the loopers and the normal path of the needles for preventing the needles from being deflected during sewing. As can be seen, such guides are quite complicated and as shown in the patent are used in conjunction with a plurality of loopers all of which are positioned on one side of the path of the needles. Other examples of guides for sewing machine needles are disclosed in U.S. Pat. Nos. 280,773 and 1,419,718.